$.$ Please write a bourne shell script that asks the user for a score. If the score is between $90$ and $100,$ then print $$you got A$,$ else if between $80$ and $90,$ then $$you got B$$ and so on$.$ If less than $60,$ then $$you failed$.$ If the user enters number not between $0$ and $100,$ then print the error message and exit the script.